A semiconductor structure and a method for forming the same are provided. The method includes forming a source/drain structure in a substrate and forming a metal layer over the source/drain structure. The method for manufacturing a semiconductor structure further includes performing an annealing process such that a portion of the metal layer reacts with the source/drain structure to form a metallic layer on the source/drain structure. The method for manufacturing a semiconductor structure further includes performing an etching process to remove an unreacted portion of the metal layer on the metallic layer and forming a contact over the metallic layer. In addition, the etching process includes using an etching solvent, and the etching solvent includes (a) a first component, including H2SO4, HCl, HF, H3PO4, or NH4OH and (b) a second component, including propylene carbonate, ethylene carbonate, diethyl carbonate, acetonitrile, or a combination thereof.